Filament coiling machine having finely adjustable coiling head



1959 w. A. FLETCHER 2,873,788

FILAMENT comma MACHINE HAVING FINELY ADJUSTABLE COIL-INC HEAD Filed Nov. 27, 1956 3 Sheets-Sheet 1 1N VENTO R @maaw ATTOR NEY Feb. 17, 1959 w. A. FLETCHER 2,373,788

' FILAMENT COILING MACHINE HAVING FINELY ADJUSTABLE comm; HEAD Filed Nov. 2'7, 1956 3 Sheets-Sheet 2 INVENTOR i mm ATTORNEY w. A. FLETCHER 2,873,788 FILA T COILING MACHINE HAVING FIN ADJUSTABLE COILINQ HEAD Feb. 17, 1959 MEN ELY 3 Sheets-Sheet 5 Filed Nov. 2'7, 1956 United States Patent .FILAMENT 'COILING MACHINE HAVING FINELY ADJUSTABLE 'COILING HEAD Application November 27, 1956, Serial No. 624,530 6 Claims. c1. 153-67) This invention relates to filament coiling machines and more particularly to an improvement in the coiling head driving mechanism of such machines. 7

A well known form of filament coiling machine, especially adapted for the manufacture of coiled filaments for incandescent lamps, utilizes a rotatable coiling head and a retractable Wire guide for placing the individual coil turns upon the mandrel in the coiling head. The coiling head is suitably driven from an intermittent drive mechanism and each cycle of machine operation for forming a coiled filament may be considered to include a drive interval during which theturns of the coil are formed and a dwell interval during which the leg portion ofthe coil is formed and severed and the coil is removed from the mandrel. He'retoforeflhe number'of turns formed on the coil during the drive interval has bee'n'de'termined approximate'ly by the gear ratio between the 'drive-shaft'and. the coiling head. v v

In the manufacture of incandescent lamp filaments, it is very important to obtain an exact number of turns and fractional turns in each individual coil and toobtain uniformity among successive coils. i

Accordingly, it is an object ofthis invention to provide an improved drive mechanism for the coiling head of a filament coiling machine which permits accurate control of the number of individual turns in a given coil.

An additional object of the invention is to provide an improved filament coiling machine adapted to terminate coiling head rotation at a predetermined angular position prior to the termination of the drive interval.

An additional object of the invention is to provide an improved coiling machine in which thecoiliug head is brought to a standstill prior to the dwell interval of the operating cycle.

In accordance with this invention, a filament coiling machine is provided having a rotatable coiling head, a drive train for imparting intermittent rotation to the coiling head, and a filament guide for placing filament wire upon the coiling head, A resilient coupling is interposed 1 betweenthe' coilinghead and the drive train and means, actuated in timed relation with the drive train rotation, are provided to arrest rotation-of the coiling head prior to the termination of the drive" interval. The resilient coupling permits relative rotation of the drive train when the coiling head is arrested and'causes the coiling head to return to its reference position in readiness for the succeeding cycle of operation.

'Amore complete understanding of the invention may be had from the detailed description which follows taken with thelaccompanying drawings in which:

Figurel is an elevation view, partially in section, of the inventive apparatus.

, Figure 2 is a plan view of the apparatus shown in Figure 1.

Figure 3 is a view, partially diagrammatic and looking in the direction of the arrow 3 in Figure 1, showing certain details of the apparatus.

2,873,788 Patented Feb. 17,1959

Figure 4 is an enlarged view taken on lines 4-4 0 Figure 1.

Referring now to the drawings, there is shown an illus trative embodiment of the invention in a filament coiling machine adapted for the manufacture of coiled filaments for incandescent lamps. In general, the machine comprises a rotatable coiling head 10 adapted to receive the free end of the filament wire and a retractable wire guide 12 for placing the individual turns of the filament wire on the coiling head. The coiling head 10 is rotatably driven through a torque reduction or speed increasing drive train 14 which in turn is driven by an intermittent drive mechanism designated generally at 16 (-Figure 3). Interposed between the coiling head 10 and the drive train 14 is a resilient coupling 18. A stop mechanism 20'is adapted to arrest the rotation of the coiling head 10 and is energized and de-energized in timed relation with the intermittent drive 16.

The coiling head 10 is supported for rotation in a standard or journal housing 24 which is mounted upon a support plate or base 26 of the coiling machine. The coiling 'head includes a hollow spindle or shaft 28 journalled in bearings 30 and is provided at one end with a spindle head 32 which is secured thereto by a key for rotation with the spindle. The hollow spindle 28 accommodates a mandrel shaft 34 non-rotatably secured to the spindle by collars 36 and 38 which are interconnected by a pin 40. At the forward end of the mandrel shaft 34 there is provided a chuck 42 in which is mounted a mandrel 44. The mandrel extends over the coiling head die 46 which is adapted to receive the free end of the filament wire 48. The filament wire is clamped to the die 46 by a springurged bell crank lever 50 mounted on the spindle head 32.

The filament wire guide 12 which includes the die member 52 feeds the filament wire to the coiling head and is adapted to be advanced to a position adjacent the coiling head die and retracted in synchronism with rotation of the coiling head to place the individual coil turns upon the mandrel 44 in a well known manner. Withdrawal of the mandrel 44 from the completed filament coil is effected by the lever 54 which is connected with the shaft 34 through a yoke and thrust bearing assembly 56. Upon the completion of the coiling operation, sliding motion of the mandrel shaft is permitted by the coaction of the collars 36 and 38 and pin 40. Since the specific form and actuating mechanism for the wire guide 12 and the mandrel withdrawal lever 54 form no part of the present invention, these components of the coiling machine are shown in fragmentary View only. 7

Rotative motion is imparted to the coiling head 10 from the drive or cam shaft 58 (Figure 3) through the intermittent drive mechanism 16. An interrupted drive gear 60 meshes with a pinion gear 52 throughout a major portion of its circumference which corresponds to the drive interval of-the machine operating cycle. A smooth or toothless segment 64 on the interrupted gear 60 corresponds to the dwell interval, of the operating cycle and, of course, imparts no rotation to the pinion 62. The intermittent drive mechanism 16 may be provided with any suitable form of synchronizer (not shown) to prevent gear clash and to afford smooth acceleration and deceleration of the drive pinion 62. The drive pinion 62 is mounted upon a stub shaft 66 which drives the gear train 14. The gear train 14 includes the gear '68, intermediate gears 70 and 72, and the final gear 74 which is rotatably mounted on a suitable bearing upon the spindle 28. The intermittent'drive mechanism 16 and the drive train 14 constitute a torque reduction or speed increasing drive between the drive shaft 58 and the final gear 74, and hence 18. This coupling comprises a helical coil spring 76 having one end secured to the final gear 74 and the other end secured to a drive plate 78 which is suitably keyed to the spindle 28. The final gear 74 and the drive plate 78 are maintained in a reference position relative to each other, .in the normal condition, by a rotation limit and the'action of the drive spring 76. The rotation limit includes an abutment element or pin 80 extending from the final gear 74 and a similar abutment element or pin 82 extending from the drive plate 78. The pins 80 and 82 are suitably utilized to secure the ends of the drive spring 76 to the gear 74 and plate 78. The spring 76 is pre-stressed to exert a torsional effort between the final gear 74 and drive plate 78 to cause these members to assume the aforementioned reference position with the pins 80 and 82 in abutment with each other. During the drive interval of the intermittent drive mechanism 16, the rotative effort transmitted through the drive train 14 to the final gear 74 rotates the latter clockwise viewing the apparatus from the coiling head in Figure l which additionally stresses the drive spring 76 and tends to separate the pins 80 and 82. Accordingly, this rotative effort is transmitted through the drive spring 76 to the drive plate 78 and thence to the spindle 23.

In accordance with this invention, precise control of the number of turns produced on the filament coil is af forded by terminating coiling head rotation at any desired angular position during the drive interval by the stop mechanism to be described presently. The stop mechanism 26 comprises a stop ring 84 including a stop element or radial shoulder 86. The stop ring is secured to the drive plate 78 in a position opposite an arresting device 88 secured to a fixed part of the machine. The arresting device 88 includes a reciprocable stop pawl 96 movable into alignment with the stop element 36 by an actuator 92, suitably a spring loaded pneumatic piston, controlled by a magnetic valve 94. The valve is provided with an inlet conduit 96 connected with a suitable source of air pressure and an outlet conduit 98 connected with the actuator 92. The magnetic valve 94 is in turn controlled by a cam actuated electrical switch 99 which includes a follower adapted to engage the cam 100 on the cam shaft 58. The cam 106 includes a lobe 162 which has an angular position relative to the interrupted gear 60 so that the switch is closed a predetermined increment before the pinion gear 62 enters the toothless segment 64 of the interrupted gear 60. The lobe 162 is of such angular extent, in the illustrative embodiment, that the switch is maintained in the closed position until the pinion gear 62 leaves the toothless segment 64. Therefore, the stop pawl 90 is projected into alignment with the stop element 86 by energization of the piston 92 prior to the termination of the drive interval and is retracted at the termination of the dwell interval.

To terminate coiling head rotation at any desired angular position during the drive interval, the stop ring 84 is angularly adjustable on the drive plate 78. For this purpose the drive plate 78 is provided with circumferential slots 104 and the stop ring 86 is secured thereto by screws 106 extending through the slots. Adjustment may be effected by loosening the screws 1%, rotating the stop ring 34 relative to the drive plate '78, and securing the stop ring in the selected position by tightening the screws.

In operation of the inventive apparatus, adjustment of the machine for winding the specified number of turns on the filament coil is accomplished in the following manner. Course adjustment is established by selection of the gear reduction ratio between the driving shaft 56 and the final gear 74. This course adjustment determines the whole number and any integral fractional number of turns on the coil since the number of revolutions of the final gear 74 for one revolution of the drive shaft 53 is equal to this ratio. Fine adjustment of the number of coil turns is obtained by adjustment of the stop mechanism 20 for a given position of the coiling head 10. The angular relation of the cam operated switch 99 and the cam lobe 102 is such that the stop pawl is projected just prior to the termination of the drive interval. For example, this angular relation may be such that the projection of the pawl occurs at approximately the beginning of the final revolution of the final gear 74. Fine adjustment of the total number of coil turns is therefore accomplished by angular rotation of the stop ring 84 to any desired position with reference to the drive train 14. For a large increment of fine adjustment, the final gear 74 may be advanced or reversed one or more teeth relative to gear 72. For small increments of fine adjustment, the screws M6 are loosened to permit rotation of the stop ring 84 to the selected position and tightened to secure the ring in place. Accordingly, during the drive interval, rotative effort is transmitted from the intermittent drive mechanism 16 through the drive train 14 to the final gear 74, through the coil spring 76 to the drive plate 78, and thence to the spindle 28 of the coil'head. During the starting and termination of the drive interval the resilient coupling 18 is effective to absorb the shock in the drive train occasioned by acceleration and deceleration. As the end of the drive interval is approached, the switch 99 is closed by the cam 100, for example, at approximately the beginning of the final rotation of final gear 7 4. At this point the magnetic valve 94 admits fluid pres-sure to the piston 92 and the stop pawl 90 is projected into the path of the stop element 86. During the final revolution of the gear 74 the stop element 86 engages the pawl 90 and positively terminates the rotation of the coiling head 10 at an angular position depending upon the adjustment of the stop ring 84. The final gear 74 continues its rotation through the final revolution and, since the drive plate 78 is locked in position, this additional rotation of the gear 74 is taken up in the coil spring 76. With the coiling head positively locked in position and at the completion of the final revolution of gear 74 the dwell interval of the operating cycle commences. During this interval the wire guide may be retracted, depending upon the specific type of machine employed, and the filament is severed to form the desired leg portion in a well known manner. During the dwell interval, the mandrel 44 is withdrawn from the coil by operation of the lever 54 and the coil is removed or transferred from the machine in any desired manner. If a given coiling head position is required for coil transfer, this latter operation is suitably performed after the stop mechanism 20 is de-energized. Upon continued rotation of the cam 100, the switch 99 is opened just prior to the end of the dwell interval. Accordingly, the stop pawl 90 is retracted and drive plate 78'and spindle 28 are free torotate under the influence of the coil spring 7 6 until the limit 82 engages the limit 80. Thus the coilinghead assumes its normal rotative position in readiness for the succeeding cycle of operation.

Although the description of this invention has been given with reference to a particular embodiment, it is not to be construed in a limiting sense. Many variations and modifications within the spirit and scope of the invention will now occur to those skilled in the art. For a definition of the invention, reference is made to the appended claims.

What is claimed is:

1. In a filament coiling machine of the type having a rotatable coiling head, a drive train for imparting intermittent rotation to the coiling head, and a guide for placing filament wire upon said coiling head, the improvement which comprises a resilient coupling interposed betweenthe coiling head and the drive train for transmitting rotation to the coiling head in one direction only, a stop element connected with the coiling head, an arresting device disposed adjacent the stopelement and adapted to arrest the motion thereof, and actuating means connected between the drive trainand the arresting device for energization of the device, whereby the coiling head is arrested during a driving cycle of said train in a predetermined angular position and relative rotation of the drive train and coiling head is permitted by the resilient coupling.

2. In a filament coiling machine of the type having a rotatable coiling head, a drive train for imparting intermittent rotation to the coiling head, and a retractable guide for placing filament wire upon the coiling head in individual coil turns, the improvement which comprises a resilient coupling interposed between the coiling head and the drive train for transmitting rotation to the coiling head in one direction only, a stop member including a stop element connected with the coiling head, said stop member being angularly adjustable with reference to the drive train, an arresting device disposed adjacent the stop member and adapted to arrest the motion thereof, and actuating means connected between the drive train and arresting device for energizing of said device during a driving cycle of said train in synchronism with the drive train rotation.

3. In a filament coiling machine of the type having a rotatable coiling head, an intermittent driving member, a speed increasing drive train driven thereby for imparting intermittent rotation to the coiling head, and a retractable guide for placing filament wire upon the coiling head in individual turns, the speed ratio of the drive train being effective to determine the number of coil turns produced by a given drive interval, the improvement which comprises a resilient coupling interposed between the drive train and the coiling head for transmitting rotation to the coiling head in one direction only, a stop member including a stop element connected with the coiling head, an arresting device disposed adjacent the stop element and adapted to arrest the motion thereof, said stop element and arresting device being relatively movable in angular relation for a given position of the coiling head to permit fractional adjustment of the number of coil turns produced in the given drive interval, and actuating means connected with the driving member for controlling energization of the arresting device during a driving cycle of said train in synchronism with the drive train rotation.

4. In a filament coiling machine of the type having a rotatable coiling head, an intermittent driving member establishing drive and dwell intervals in each cycle of machine operation, a speed increasing drive train driven by the driving member for imparting rotation to the coiling head during the drive interval, and a retractable guide for placing filament wire upon the coiling head in individual turns, the speed ratio of the drive train being effective to determine the number of coil turns produced during the drive interval, the improvement which comprises a resilient coupling interposed between the drive train and the coiling head for transmitting rotation to the coiling head in one direction only, stop means connectable with the coiling head for arresting rotation thereof, actuating means connected with the driving member for causing energization of the stop means prior to the termination of the drive interval whereby the relative rotation of the coiling head and drive train from an initial position determines the fractional number of coil turns, and for causing deenergization of the stop means prior to the termination of the dwell interval whereby the resilient coupling rotates the coiling head relative to the drive train in said one direction to said initial position in readiness for a succeeding cycle.

5. The invention defined in claim 4 wherein said resilient coupling comprises a driving element connected with said drive train, a driven element connected with said coiling head, a coiled spring having one end connected with the driving element and the other end connected with the driven element, and rotation limit means extending between said elements to establish a reference position of said elements relative to each other and to maintain said spring in a stressed condition.

6. The invention defined in claim 4 wherein said resilient coupling comprises a driving element connected with the drive train, a driven element connected with the coiling head, a coiled spring having one end connected with the driving element and the other end connected with the driven element, rotation limit means extending between said elements to establish a reference position of said elements and to maintain'said spring in a stressed condition and wherein said stop means comprises a stop element on said driven element, means for adjusting the stop element angularly with reference to the drive train, and a movable stop pawl aligned with said stop element and actuated by said actuating means.

References Cited in the file of this patent UNITED STATES PATENTS 606,525 Dunning June 28, 1898 844,206 Sommer Feb. 12, 1907 1,045,900 Sleeper Dec. 3, 1912 1,368,297 Sleeper Feb. 15, 1921 1,828,413 Holmes Oct. 20, 1931 1,935,137 Thomas Nov. 14, 1933 2,155,388 Anderson Apr. 25, 1939 2,179,296 Iden Nov. 7, 1939 2,541,232 Forster Feb. 13, 1951 2,801,670 Wolf Aug. 6, 1957 FOREIGN PATENTS 15,245 Great Britain July 10, 1903 

